More context: I help a friend who has been repairing stuff since the 1950s. I've learned from him, and from the germanium transistors we encounter (after decade

More context: I help a friend who has been repairing stuff since the 1950s. I've learned from him, and from the germanium transistors we encounter (after decades in light service) that they tend to "go soft" with use, as do vacuum tubes. You end up replacing them with "new" germanium transistors, or re-bias the circuit to work with silicon transistor replacements that have no such issues.